Structural analysis of the putative SARS-CoV-2 primase complex

J Struct Biol. 2020 Aug 1;211(2):107548. doi: 10.1016/j.jsb.2020.107548. Epub 2020 Jun 11.

Abstract

We report the crystal structure of the SARS-CoV-2 putative primase composed of the nsp7 and nsp8 proteins. We observed a dimer of dimers (2:2 nsp7-nsp8) in the crystallographic asymmetric unit. The structure revealed a fold with a helical core of the heterotetramer formed by both nsp7 and nsp8 that is flanked with two symmetry-related nsp8 β-sheet subdomains. It was also revealed that two hydrophobic interfaces one of approx. 1340 Å2 connects the nsp7 to nsp8 and a second one of approx. 950 Å2 connects the dimers and form the observed heterotetramer. Interestingly, analysis of the surface electrostatic potential revealed a putative RNA binding site that is formed only within the heterotetramer.

Keywords: Crystal structure; Primase; RNA; SARS-CoV-2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Betacoronavirus / chemistry*
  • Binding Sites
  • Coronavirus RNA-Dependent RNA Polymerase
  • Crystallography, X-Ray
  • DNA Primase / chemistry*
  • DNA Primase / metabolism
  • Models, Molecular
  • Multiprotein Complexes
  • Protein Conformation
  • Protein Multimerization
  • RNA / metabolism
  • SARS-CoV-2
  • Viral Nonstructural Proteins / chemistry*
  • Viral Nonstructural Proteins / metabolism

Substances

  • Multiprotein Complexes
  • NS8 protein, SARS-CoV-2
  • Viral Nonstructural Proteins
  • RNA
  • DNA Primase
  • Coronavirus RNA-Dependent RNA Polymerase
  • NSP7 protein, SARS-CoV-2